Availability of UAV Fleet Evaluation Based on Multi-State System

Abstract

Unmanned Aerial Vehicle (UAV) applications are extended extremely. Some applications need to use several UAVs for a general mission which can be considered a UAV fleet. One of the important characteristics for the evaluation of a UAV or UAV fleet is reliability. There are studies in which methods for analysis of their reliability are considered. Reliability analysis of UAV fleets is less frequently studied, although a single UAV cannot be performed in many applications and requires the involvement of multiple UAVs. Typically, this analysis is based on evaluating two states as operational/functioning and faulting. This paper proposes a new method to calculate the availability of a UAV fleet as one of the reliability characteristics. Unlike well-known UAV fleet analysis approaches, in this paper, the availability is studied based on a mathematical model of a Multi-State System (MSS). MSS allows us to examine more than two states (operational and faulty) of the system, so this analysis is more detailed. In this paper, based on MSS, the analysis of various topologies of UAV fleets is implemented. This mathematical model is used for the analysis and evaluation of topologies of homogeneous and heterogeneous UAV fleets, which can be irredundant or redundant hot stable systems. The interpretations of different topologies of fleets as typical structures of MSS (series, parallel, k-out-of-n) are considered. New mathematical definitions of the availability of UAV fleets of different topologies based on MSS structure function are proposed. These definitions allowed us to consider the influence of the number of UAVs on the UAV fleet availability and compare the availabilities of considered topologies of fleets.